Liquid hydrocarbon fuels containing alkali metal salts of alkyl and dialkyl-aminoalkyl phenols, as antiknock agents

ABSTRACT

Liquid hydrocarbon fuel compositions are provided containing antiknock quantities of alkali metal salts of alkyl and dialkylaminoalkyl phenols.

United States Patent 1 Heiba et al.

m1 3,770,397 1 Nov. 6, 1973 LIQUID HYDROCARBON FUELS CONTAINING ALKALI METAL SALTS OF ALKYL AND DlALKYL-AMINOALKYL PHENOLS,'AS ANTIKNOCK AGENTS [75] Inventors: El-A hmadi l. Heiba; Stamoulis Stournas, both of Princeton, NJ.

[73] Assignee: Mobil Oil Corporation, New York,

22 Filed: June 19, 1972 21 App]. No.: 263,904

[52] US. Cl... 44/75, -44/72, 252/386 [51] Int. Cl C011 1/22 [58] Field of Search 44/72, 75; 252/386 Primary Examiner-Daniel E. Wyman Assistant, Examiner-Andrew H. Metz Att0meyAndrew L. Gaboriault et a1.

[57] ABSTRACT Liquid hydroearbon fuel compositions are provided containing antiknock quantities of alkali metal salts of alkyl and dialkyl-aminoalkyl phenols.

8 Claims, No Drawings.

LIQUID HYDROCARBON FUELS CONTAINING ALKALI METAL SALTS OF ALKYL AND DIALKYL-AMINOALKYL PIIENOLS, AS

ANTIKNOCK AGENTS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to liquid hydrocarbon fuel compositions having improved antiknock properties. In one of its aspects, the invention relates more particularly to liquid hydrocarbon fuel compositions intended for use in internal combustion engines containing novel and effective antiknock agents.

2. Description of the Prior Art I 7 Various antiknock agents have, heretofore, been suggested and employed for use in liquid hydrocarbon fuels, particularly in fuels employed in internal combustionengines. In such engines, it is highly desirable, from a standpoint of economics that combustion of the fuel occurs at relatively high compression ratios. Such high compression ratios concomitantly necessitate the use of fuels having relatively high octane numbers to insure knock-free operation.

The most widely known antiknock agents include: aniline and alkali derivatives thereof such as N- methylaniline and N-ethylaniline; phenylenediamines; nitriles, proprionitrile'; tertiary alkyl ethe'rs; tetramethyl lead; and tetraethyl lead. In general, however, none of these antiknockadditives have proved to be entirely satisfactory in effectively raising the octane number of the fuel without also exhibiting'other undesirable properties of varying importance.

SUMMARY .OF THE INVENTION In accordance with the present invention, new and improved liquid hydrocarbon fuel compositions are provided containing an antiknock quantity of alkali metal salts of alkyl and dialkyl-aminoalkyl phenols. These compoundsare represented by the following general formula:

ill NR1, R2

found that these novel phenate salt compounds effect improvement in both Motor Octane Number and Research Octane Number in fuels. In general, these novel antiknock additives are employed in amounts from about 0.1 to about 5 percent, and preferably from about 0.1 to about 2 percent, by weight, of the total weight of the fuel composition.

7 DESCRIPTION OF SPECIFIC EMBODIMENTS The antiknock agents of the present invention are prepared, in general, by the following method:

One mol e of the appropriate phenol is moxed with 1.1 mole of 25 percent aqueous alkyl or dialkyl amine. To this admixture, 1.1 mole of 37 percent formalin is added dropwise, with stirring. The reaction temperature is not. allowed to rise above 25C. for optimum results. After the addition is complete, 200 ml. of saturated salt solution is added and the mixture is extracted three times with 200 ml. ether. The ether fractions are combined and extracted twice with 250 ml. of 15 percent aqueous hydrochloric acid. The acid fractions are then combined, made alkaline (pl-I9) and extracted twice with 200 ml. ether. The ether fractions are then combined, dried over anhydrous sodium sulfate, and the ether is evaporated off to yield the desired alkyl or dialkyl aminoalkyl phenol. This phenol is transformed to its alkali metal salt by treating it with the corresponding alkali metal hydroxide, hydride, alkoxide or amide in an appropriate solvent such'as tetrahydrofuran, methanol, ethanol or liquid ammonia.

The following examples and comparative data will serve to illustrate the preparation of the novel antiknock compounds of the present invention and their efficacy in improving the octane number of liquid bydrocarbon fuels. It will be understood, however, that it is not intended that the invention be limited to the particular antiknock compounds or the particular liquid hydrocarbon fuels containing these compounds, as described. Various modifications of these antiknock additives and liquid hydrocarbon fuels can be effectively employed, as will be readily apparent to those skilled in the art.

EXAMPLE 1 Preparation of the lithium slat of 2-dime- 5 thylaminomethyl-4-cresol To a mixture of 120 grams 4-cresol and 180 ml. 25 percent aqueous dimethylamine was added 200 grams of 37 percent formalin, dropwise and with stirring. The temperature was not allowed to rise above 25C. After the addition was completed, 200 ml. of salt solution were added. The mixture was extracted three times with 200 ml. ether, the ether fractions were combined and extracted twice with 250 ml. of 15 percent aqueous hydrochloric acid. The acid fractions were combined, made slightly alkaline (pl-I9) and extracted twice with 200 ml. ether. The ether fractions were combined,

. dried over anhydrous sodium sulfate and the ether was evaporated off to yield grams of 2-dimethylaminomethyl-4-cresol. This cresol was transformed to the lithium salt by one of the following methods:

a. To a slurry of 1.2 grams of lithium hydride in ml. tetrahydrofuran was added 2-dimethylaminomethyl-4-cresol (16.5 grams) and the mixture was stirred at room temperature for 8 hours. The mixture was then filtered and the tetrahydrofuran evaporated off to yield 16.6 grams of the lithium salt of the above cresol.

b. Lithium hydroxide monohydrate (4.2 grams) was added to a solution of 8.2 grams 2-dimethylaminomethyl-4-cresol in 300 ml. ethanol. The mixture was refluxed under a Soxhlet extractor containing molecular sieves for 3 hours. The mixture was then filtered and the ethanol was evaporated off to yield 7.8 grams of the lithium salt of the above cresol.

c. The same procedure as in (b) was used, except that, instead of ethanolic lithium hydroxide, a solution obtained by dissolving 1.0 grams lithium in 200 ml. methanol was employed.

This compound, prepared by the above-described EXAMPLE Pmfledure crew was ansfmmed F Lithium salt of Z-(dimethylaminomethyl)-5-cresol mhmm Salt employmg method had the followmg This salt was prepared as described for its isomer in Structure: Example 1, except that 3-cresol was used as a starting V material.

I H CH3 This compound had the following structure:

CH3 O EXAMPLE 2 Sodium salt of Z-dimethylaminomethyl-4-cresol l5 EXAMPLE 6 The sodium salt was prepared the same manner as the lithium Salt, describedv above, f 2- Sodium salt of Z-(dimethylammomethyl)-5-cresol dimethylamino-4-cresol and sodium hydride in tetrahy- This Salt was P p as described for its isomer in drofuran, sodium hydroxide in ethanol or sodium metal Example 2 in m th nol, This compound had the following structure:

This compound, preparedby the above-described procedure in which thecresol'was transformed to the 0N9,

sodium salt employing method (a), had the following l structure: (|J-N CII3 O 1r cm (I: l CH3 -NCHJ 7 CH; EXAMPLE 7 Lithium salt of 2-(diethylaminomethyl)-4-cresol This salt was prepared in accordance with the proce- EXAMPLE 3 dure of Example 1, with corresponding reactant substi- Potassium salt of 2-dimethylaminomethyl-4-cresol tlltlofl- This potassium salt was prepared the same way as the T p n d he following structure: equivalent lithium and sodium salts, except 2-dimethylaminomethyl-4-cresol was treated with potassium- Li 7 t-butoxide in tetrahydrofuran. r l H This compound, prepared by the above-described 40 lNO2H'5 procedure was transformed to the potassium salt, em- H ploying method a, and had the following structure:

CH3 0K l l m I l-N-CH; EXAMPLE 8 H Lithium salt of 2-(di-n-butylaminomethyl)-4-cresol This salt was prepared in accordance with the proce- Cm dure of Example 1, with corresponding reactant substitution;

This compound had the following structure: EXAMPLE 4 Lithium salt of 2,6-bis-(dimethylaminomethyl)-4- OLi cresol I H This cresol was preparedas described in Example 1, except that, after the addition of formalin, the mixture H was heated under reflux for 4 hours. The lithium salt was prepared as described in Example 1. CH This compound had the following structure: 3

EXAMPLE 9 Lithium salt of 2-(di-iso-butylaminomethyl)-4-cresol This salt was prepared in accordance with the procedure of Example I, with corresponding reactant substitution. CH: This compound had the following structure:

These three salts'of Examples 7, 8 and 9 were prepared as described for the dimethylaminohomologue in Example -l, except that, in place of dimethylamine, di ethylamine, di-n-butylamine, and di-iso-butylamine were used respectively.

EXAMPLE 10 Sodium salt of 2-(di-n-butylaminomethyl)-4-cresol This compound had the following structure:

V CHa' EXAMPLE 1 1 Sodium salt of 2,6 -bis-(dimethylaminomethylj-4- cresol This compound had the following structure:

ONa OH: .H I

These sodium salts of Examples 10 and 11 were prepared from the corresponding cresols as'described in The efficacy of the novel antiknock compounds of the present invention for, improving the antiknock properties of liquid hydrocarbon fuels will be apparent from the foregoing examples and comparative data. in these novel antiknock compounds the alkyl and dialkyl aminoalkyl group is of significant importance in imparting solubility characteristics of the phenate salts. Optimum improvement is influenced by the substituents of the aromatic ring. An unusual feature of these phenate is that they lead to a greater improvement in the motor octane number than the research octane number. This discovery is of great significance for gaso lines that must meet the road requirements of modern automobiles which are more dependent on the motor octane number of the fuel rather than on its research octane number. Another important aspect of these phenates is that the alkali metals are volatile and therefore do not lead to deposits either in the engine or in catalytic afterburners. It will be understood, moreover, that the novel antiknock compounds of the present invention may be advantageously employed in any liquid hydrocarbon fuel composition which is suitable for use in a combustion engine, regardless of the purpose for which the engine is designed. The antiknock effect of the compounds of the present invention is independent of other antiknock agents that may be concomitantly employed. Thus, the compounds of the present invention will increase the antiknock ratings of liquid hydrocarbon fuels even though other antiknock agents may also be present. It will also be understood that other additives intended for the purpose of imparting other improving properties to the fuel may be employed in combination with the present antiknock compounds. Hence, metal deactivators, antioxidants, anti-rust, anti-stalling and ignition control compounds may also be employed in these fuels.

Although the present invention has been described with certain specific and preferred embodiments, for purposes of illustration, .it will be understood that various modifications and adaptations thereof, which will be obvious to those skilled in the art, may be made without departing from the spirit of theinvention.

We claim:

1. A gasoline composition containing an antiknock quantity of at least one member of the group consisting of alkali metal salts'of alkyl aminoalkyl phenols and alkali metal salts of dialkyl aminoalkyl phenols.

2. The composition of claim 1 wherein said antikn'ock compound comprises the lithium salt of 2 -dimethylaminomethyl-4-cresol.

3.-The composition of claim 1 wherein said antiknock compound comprises the lithium saltvof 2- TABLE I Antiknock effectiveness of alkali metal salts of alkyl and dlalkylaminoalkyl phenols Auti- Antiknock Base knock RON Base compound Conc., fuel, fuel, apprefuel, examples gin/liter RON RON ciation MON Antiknock MON fuel, appre- MON ciation 83.8 1. 3 85. 0 2.5 86. 6 4. 1 81. 6 O. 2 83. 4 1. 2 83. 3 0. 8 82. 6 0. l 82. 9 0.8 83. 5 0. 9 83.3 0. 7 83. (l 0. 4

(dimethylaminomethyl)--cresol.

4. The composition of claim 1 wherein said antiknock compound comprises the sodium salt of 2- (dimethylaminomethyl)-5-cresol.

5. The composition of claim 1 wherein said antiknock compound comprises the lithium salt of 2-(diethylaminomethyl)-4-cresol.

6. The composition of claim 1 wherein said anticompound.

75, 3? UNITED STATES PATENT OFFICE v CERTIFICATE OF CORRECTION mm No. 3,77 ,397 Nov m r 1973 humor) EL-AHMADI I. HEIBA and STAMOULIS STOURNAS It is certified that error appears in the above-identified patent and that "16! Letters Patent are hereby corrected an shown below:

Column 1, line 68, "moxed" should read --mixed-.

Column 2, line 32, 'slao" should read --salt--.

Column 3, Example 2, in the formula Column L, Example 6, in the formula should read Q Column 3, line ll, "a" should read -'(a)-.

Signed and sealed this 16th day of'April 197L (SEAL) Attest:

EDWARD I LFLETCHELJR. C. MARSHALL DANN Attesting Officer 7 V Commissioner of Patents 

2. The composition of claim 1 wherein said antiknock compound comprises the lithium salt of 2 -dimethylaminomethyl-4-cresol.
 3. The composition of claim 1 wherein said antiknock compound comprises the lithium salt of 2-(dimethylaminomethyl)-5-cresol.
 4. The composition of claim 1 wherein said antiknock compound comprises the sodium salt of 2-(dimethylaminomethyl)-5-cresol.
 5. The composition of claim 1 wherein said antiknock compound comprises the lithium salt of 2-(diethylaminomethyl)-4-cresol.
 6. The composition of claim 1 wherein said antiknock compound comprises the lithium salt of 2-(di-iso-butylaminomethyl)-4-cresol.
 7. The composition of claim 1 containing from about 0.1 to about 5 percent, by weight, of the antiknock compound.
 8. The composition of claim 1 containing from about 0.1 to about 2 percent, by weight, of the antiknock compound. 